A mountain is suddenly hit by a series of big explosions. Penelope is the one who activated the explosives, and she is thanked by Sir Harry for coming all this way to open the pass. She says it was her pleasure, as a little bit of excitement is welcome now and again. Harry asks her to go to the celebration party, but she declines, saying that Parker is will be waiting with FAB 1. She wants to get to her little farm before nightfall. Harry says he'll drive her down in his jeep.
Down below, the bulldozers begin to shovel debris out of the way. A much larger construction vehicle then moves over the mountain, laying down a new road as it goes. Harry and Penelope arrive at the spot where FAB 1 is parked. Penelope thanks Harry for inviting her here. Harry says that next time she'll have to stop for a few beers.
Parker says he's sorry to hurry Penelope, but she did say how she wanted to look at her sheep before retiring. Penelope and Parker head off to the farm in FAB 1, but Penelope says she'll call Jeff Tracy, as she has a little idea. She gets through to Tracy Island and says what she did to the mountain. She's now going to her farm, but has an idea: she knows Jeff hasn't had a vacation in at least 18 months.
She thinks he should join her here in Australia, and spend a few days on her farm. She'll make certain he's not disturbed, so he can relax completely. She wants to know when she can expect him, but he says it's not that simple. An emergency call could come through at any time, he has to organize things. Scott says they'll still be here and can follow procedure.
Virgil says he agrees with Penelope, and wants his father to have a rest. Jeff thinks this is a plot to get rid of him, and says he doesn't need a rest. Penelope says the boys agree with her, so she expects Jeff this evening -she insists he comes. She then ends the call. Jeff tells everyone they must understand the problems with him going.
He asks Alan and Tin-Tin, and Alan says sure. But Alan asks to be excused, so he and Tin-Tin can go and play tennis. Jeff tells Gordon and Brains that it isn't that he doesn't want to go, it's just there could be an emergency. Neither Gordon or Brains respond, so Jeff says he'll go to Australia, if that's what they all want!
Scott thinks that's great. The first problem is who is going to take his place. Virgil suggests Scott does, because he's the eldest. Scott thinks it's swell of them to put him in the hot seat, but his job is to fly Thunderbird 1. Jeff tells them to hold on -he's still giving the orders around here, as he hasn't gone yet. He tells Scott he's next in line, so he'll take his place. Virgil is to remain in charge of Thunderbird 2, and Gordon will use Thunderbird 4. Jeff says Alan will have to pilot Thunderbird 1, as only rarely do they have to use Thunderbirds 1 and 3 on the same operation. Scott tells Alan he's used to high speed, so he'll be taking over his old job. Jeff says he'll check things with John.
John thinks it's great is father is going to Australia. Jeff says before he hands over to Scott, he wants to know if everything's ok. John says nothing much is happening to concern them, expect the World Navy are out on exercise in the Atlantic. In the waters, several navy ships move out. The Captain of one says to prepare to commence gyropedo explosives tests. The target vessel is moved into position. The Captain says if these new weapons are successful, they'll revolutionize undersea firepower.
A lieutenant says their submarine is adopting combat position now, 100 miles from the target vessel. Elsewhere in the sea, a submarine moves towards the target vessel. The crew inside it have the submarine dive.
At Tracy Island, Jeff reports he's airborne. He reminds Scott to keep him informed. Scott tells him to relax, as he'll call if they have any problems. Jeff says so long, and leaves the island via a jet. Scott was worried their father would change his mind, he sure worries about them. Virgil says he can understand that, as their father has never left them on their own before. Alan asks what Scott's first decision will be. Scott says that's easy: he'll contact John in Thunderbird 5.
John says hi to Scott and asks what's wrong. Scott says nothing, so John asks why he's calling. Scott just wants to know how things are, so John says things are still quiet. He does mention that the World Navy are now getting ready for their target shot. Out at sea, the Captain says to alert all vessels in the vicinity and warn the drilling rig Seascape.
At Seascape, the crew are informed that the Navy is about to commence target practice, and there could be a number of nuclear explosions. When rig superintendent Frank Hooper hears this he decides to speak to them himself. He tells them that he doesn't like the sound of what they just said.
The lieutenant says that all the explosions will be beneath the surface, and out of the 40 rigs in the area, theirs is the nearest. But he insists that there is absolutely no chance of any danger. Frank tells them he hopes they're right, then ends the call. He tells O'Shea the Navy are always bellyaching about the number of new rigs going up, but no one is allowed to complain about their explosions. Meanwhile, the submarine deploys two gyropedoes, which remain along side it.
The crew set the targeting positions for the gyropedoes and fire them at the target vessel. They notice one of the gyropedoes is going off course, so they attempt to correct it. The other gyropedo hits the target vessel and destroys it. The other one veers off course, so the crew are told to destroy it. But when they try the self destruct, it won't work.
The other gyropedo ends up shooting out of the water then going back down into it. It ends up striking the ocean bed, where it explodes. John hears the news and reports it to Scott. Scott asks what the Navy's reaction is, and whilst John says a lot of people seem to be hopping mad about it, there seems there's no danger.
He says that he's overheard a call from a guy at Seascape called Hooper, who has said the water is still boiling. At Seascape, Hooper starts giving out lots of orders and has all crew put on amber alert. The Seascape's balance stabilizers are shot out into the water and the rig is raised up by ten feet.
Parker is contacted by Jeff, who requests permission to land. Parker says Penelope is out counting her sheep, as she thinks one is missing. Jeff laughs and thinks he must be kidding, as there must be 200,000 animals on the station. Parker says there's 200,0007, but Penelope can only find 200,0006. Jeff asks if he's clear to land, and Parker says he is. Outside, Penelope is still counting the sheep, but then hears Jeff's jet.
Penelope returns home, and tells Jeff she's so pleased he managed to get away for a while. She wants him to tell her about the boys and everyone else, but Jeff says that reminds him: he'd better call them and say he's arrived. Penelope says the reason she invited him was because he needed a rest. She'll allow him make this one call, but then he needs to promise her he'll try to forget all about the island. Jeff says ok, but he'd be happier checking in now and then. Penelope thinks Scott and the boys will be in bed, but Jeff thinks that Scott will be wide awake. Jeff makes the call and Scott answers. Scott says there have been no problems, so Jeff tells him to take it easy.
Scott then calls Thunderbird 5 again. Scott asks how things there are, and John says it's all quiet. Scott asks about that atomic explosion, but John says there have been no problems there, the sea's calmed down. At Seascape, Hopper tells Cravitz that the sea has settled, but he's still annoyed that those Navy guys allowing this to happen. It's bad enough being stuck out here in the middle of the Atlantic without the Navy trying to send them under.
A few hours later, there's an explosion on the sea bed. A fire column shoots out of the sea near Seascape. Cravitz says it's around the same position as the earlier explosion, so Hooper shouts to sound the alarms. He makes a radio call and alerts all stations that a fire jet has been sighted 30 miles to the west. He's not certain what the cause is, but he reckons a gas field has been blown.
John contacts Scott and says it looks like that atomic explosion caused more damage than was first thought. Hooper has sent out an alarm call, and there's a 200 foot jet of fire blazing up 30 miles from the rig. Scott asks if the guys on Seascape are in danger, but John says it's not certain yet. Scott tells him to contact them, just as Brains comes over. Scott asks him what his thoughts are, but he says it's too early to say. Meanwhile, John contacts Seascape and asks what the dangers are. Hooper says that atomic explosion fractured the seabed, but the heat has taken a few hours to penetrate through to the gas field beneath the ocean floor. This particular gas pockets stretches 40 miles to the west of Seascape's position.
Brains says it's hard to estimate how real the danger is. There could be an explosion causing a massive tidal wave which would spread to both coasts of the Atlantic. Scott wonders if they should get involved or not, but Brains says it's up to him, as he's in command. Scott wonders what his dad would do. At the ranch, a newsflash is shown on TV, reporting on what's happened in the Atlantic. Parker asks if he should wake Jeff, but Penelope says Jeff has come here to get away from those kind of problems.
However, Jeff says he heard the newscast, but he says he's not worried about that fire jet. Nobody has been hurt, and Scott will keep a check on the situation. He'll realize that this is not a job for International Rescue. But at Tracy Island, Scott tells Brains to call the boys -this is a job for International Rescue, Thunderbirds are go! Alan soon takes off in Thunderbird 1, and says he's proceeding to the danger zone.
Scott tells Virgil and Gordon to take pod 4 and the sealing device. As they head out in Thunderbird 2, Alan arrives at Seascape in Thunderbird 1. He passes by the fire jet and requests permission to land on the rig. Hooper tells him to use the heliport platform. Alan thinks this isn't going to be easy, but he manages to land Thunderbird 1.
He tells Scott he's landed in one piece, so Scott tells him that Virgil and Gordon are on the way. Virgil reports his ETA Scott. Tin-Tin tells Scott his first mission with him in control is underway. Brains thinks Jeff would be proud if he knew how Scott was handling the situation.
Scott asks if he's suggesting he calls his father. He thinks right now he'd be fast asleep, but he's actually wake. Penelope knocks on the door and says it looks like he's been awake all night. Jeff says he has, he couldn't sleep thinking about that fire jet report. Penelope reminds him he'd said earlier that Scott wouldn't put International Rescue into operation. Jeff wants to call base, just to put his mind at rest. Penelope tells him to rest and leave it to the boys.
Jeff tells her she doesn't understand, but she says she does. She tells him he's a good father who's naturally anxious. She asks him again to just relax, so Jeff tells her she's right. He says he'll get some rest now. Meanwhile, Thunderbird 2 arrives at the fire jet. Virgil reports he's arrived at the danger zone and is about to release the pod.
Pod 4 hits the water and its door opens up. Thunderbird 4 then launches, dragging along with it the large sealing device. Gordon has Thunderbird 4 submerge, and the sealing device successfully moves under the water with it. He heads towards the source of the fire jet.
Alan has set up his mobile control and tells Scott there hasn't been any word from Gordon yet. Virgil asks Gordon how it looks, and Gordon says he's going to have to take Thunderbird 4 around the fire jet. He has Thunderbird 4 move around the fire, then swings around to get the sealing device over the source of it.
The sealing device is placed over the fire jet, and Gordon activates its rocket clamps. He then has the compression valves activated, which cause the fire jet to stop. Gordon tells Alan that the fire has been extinguished.
Alan acknowledges him and tells him to return to Thunderbird 2 and base. Later on, after International Rescue have left, Hooper says what an outfit they are, as they stopped the fire from spreading. O'Shea says he's not so sure. He looks on the seismograph and says it's picking up some pretty violent waves.
Back at Tracy Island, Scott tells everyone they did it. Virgil tells him he was great, as he didn't panic and didn't put a foot wrong. Alan thinks Scott could do their father out of a job. Scott then gets a call from Jeff, who says he just heard the newscast: International Rescue capped that fire jet. Scott says they sure did, and they were successful. However Jeff then gets angry, saying that International Rescue should never have got involved. International Rescue isn't just a lot of machinery for putting out fires, it's a serious business. Scott says that fire could have caused a disaster, but Jeff says they aren't dealing with chances and they can't afford to make mistakes. He says he's flying home now.
Virgil tells Scott that their father must have thought he made the wrong decision, although personally he thought Scott got it right. Penelope asks Jeff if he's really angry, and he says sure. Then he says he's not angry with Scott, he's just worried. He meant every word he said earlier, but Penelope asks if that includes the bit about flying straight home. Jeff says he sure did, but Penelope thinks he's quite wrong. She thinks he'll make a big mistake if he does that, as he's made his point now. Scott won't go out on call now unless it's absolutely vital.
Jeff guesses she's right, and thinks Scott must run the show on his own without any interference from him. As Penelope goes off to call Scott, Parker tells Jeff he's packed his things and asks if he wants them put in the aircraft. Jeff says he's staying for a couple more days. Parker mutters some people should make up their minds. Penelope calls Scott and tells him Jeff will be staying after all. Scott tells Virgil that their dad must not have been as mad as he sounded.
At Seascape, another fire jet erupts from the sea, so Hooper tells O'Shea to make a call to International Rescue. John reports that the gas field has blown again, and whilst the sealing device worked, this is another fire jet five miles to the east of the last one. Scott asks Brains what gives. Brains says the first explosion must have moved some unstable rock, producing pockets of oxymetrigen in the cavities. These have then been ignited by the fire under the seabed. He guesses the reason why the whole gas field hasn't gone up is because the flame is traveling until it finds the next weakest point, and that point could well be Seascape! Scott asks what they can do. Brains suggests sending Thunderbird 4 down and fire strategically placed missiles to cause a fracture in the rock strata, to stop the fire spreading.
Scott asks why can't the Navy do that, and Brains says they don't have the right type of equipment. Scott says that'll save Seascape, so Virgil says what are they waiting for? But Scott tells him to hold on. The alternative plan is to let the Navy airlift the crew of the Seascape and let the gas field burn itself out. Virgil says they don't know how long that gas will keep on burning, but Scott says so what? Ships can automatically avoid the area, so as he sees it, this isn't a job for International Rescue.
Gordon think Scott has changed in the last couple of hours. Scott says sure he's changed -two hours ago their dad hadn't given him a bawling out. He's not going to do it again. It's his decision, and he's figured that normal methods of rescue are adequate, At Seascape, O'Shea says that International Rescue aren't coming. Instead, the Navy are coming to airlift them off the rig, but it'll be two hours before they get here. Hooper thinks the Navy must be 500 miles away, and O'Shea says they are -they'd moved position after the first fire was fixed.
A second fire jet then shoots out of the water. This causes a wave which hits Seascape, damaging one of its support struts. Hooper and O'Shea realize they're going to have to check the extent of the damage. Hooper says they'd better take a look at the other supports, as those could slip too.
John reports that the Seascape is in trouble, as a support column has slipped. Scott asks what the crew is doing about it, and John says that Hooper and O'Shea are going down in a diving sphere. At the Seascape, the diving sphere is lowered into the water. Hooper says this looks serious, he can see at least six bolts sheared at the base. O'Shea thinks maybe they could fix it if they got their scuba diving gear and renewed the bolts.
Another fire jet then shoots up, which causes another wave. This causes more damage to the support strut and also causes the diving bell to crash to the bottom of the sea. Hooper and O'Shea are both ok, but Hooper says they're now trapped down here as the winch has been severed. They're only hope is that the control center has registered their position.
John reports they've got a real emergency on their hands now, as those two guys are trapped in the diving sphere at the bottom of the rig. Brains says the drilling rig is obviously the next weakest point, and the fire will certainly use the borehole as an outlet. Scott says this is really it, International Rescue is the only hope for those guys. He tells Alan to take Thunderbird 1 out to Seascape. Thunderbirds 2 and 4 will be needed to get Hooper and O'Shea to the surface before the rig blows. Thunderbird 1 soon takes off.
Not long after, Thunderbird 2 is launched, again carrying pod 4. The World Navy starts launching some helijets, and report that they can take care of the men on the rig. One of them asks what they can do about the diving sphere. The Captain says they can do nothing, from what he understands the sphere is tangled up in half a ton of metal. Their submarines and divers could never shift that, so it's a job for International Rescue.
Alan says he's approaching the danger zone now, and will relay information to Thunderbird 2 as soon as he touches down. He lands Thunderbird 1 on Seascape. In the diving sphere, O'Shea asks what's happening. Hooper tells him not to worry, as they'll soon have them out.
At the ranch, everyone hears a newsflash on the radio. The reporter says that the drilling rig Seascape is near collapse, as fires rage in the Atlantic ocean. Two rig crewmen are trapped at the base of the Seascape in a diving sphere, and it's understood that International Rescue is on the scene. Jeff tells Penelope there's a real emergency, and the boys will need his help. Back at the island, Scott asks Tin-Tin for more coffee. He then asks Virgil if he's at the danger zone.
Scott says he is, and is about to drop the pod. Scott tells him to tell Gordon he's got to work fast, as the fire could hit that borehole at any time. Virgil drops pod 5 into the sea, and Thunderbird 4 launches out of it. O'Shea they're never going to get them out of here, not with all that metal on top of them. Hooper tells him to take it easy.
Penelope asks Jeff if he's really determined to go back to the island. Jeff says he's got to, there's a real emergency. Penelope says very well, but she's coming to. At the Seascape, the Navy helijets start to take the crew off the rig. Cravitz tells Alan that there's still 16 more people to evacuate, so this is going to take some time.
Alan reports to Scott that operation liftoff is in full swing, but the problem is they don't know exactly how long they've got. Scott tells him to work as fast as he can. Gordon then contacts Alan and tells him that the pressure and the damage has jammed the sphere hatch. He's going to have to cut through the guide cables holding the sphere to the support column.
Alan reports to Scott, but then says he just felt movement -the rig is slipping some more! He says he's worried about Thunderbird 1, so Scott asks how many more crewmen are left to get off the rig. Alan says six, so Scott tells him to get his gear into Thunderbird 1 and operate from the air. Meanwhile, Thunderbird 4 starts cutting through the cables.
There is then an explosion above the damaged support strut, causing the rig to slip again. The last Navy helijet takes off, but Thunderbird 1 starts to slide. Virgil tells Alan to get Thunderbird 1 up fast, so Alan takes off just in time. He says he's cleared the rig, but will remain on hover in the danger zone.
Gordon finishes cutting through the cables, as more wreckage continues to drop down. He says the cables are free, so he's going in to shift the rest of the debris. He then sees even more wreckage drop down and asks what's happening to the rig, as the wreckage is going to smash the craft to pieces. Alan says the Seascape is breaking up and asks him how long he'll be. Gordon says he'll let him know.
He uses Thunderbird 4 to nudge the worst of the debris away from the sphere. He says he'll try to haul the sphere free with the electromagnet. He activates the electromagnets, which come out of the front of Thunderbird 4. Virgil sees turbulence on the rig, so Alan tells the last man to get on the helijet fast, and tells Virgil to get clear.
The rig then explodes, so Alan tells Gordon to move fast. As the entire rig catches fire, most of it begins to fall apart and crash into the sea. Gordon uses the electromagnets to grab onto the diving sphere and move it out of the way. He tells Virgil to make ready with the grabs, so Virgil tells him to take the sphere to the surface.
Thunderbird 4 surfaces, bringing the sphere along with it. Hooper says International Rescue have saved them, whilst O'Shea figured they were dead for sure. Virgil lowers the grabs out of Thunderbird 2, which grab onto the diving sphere and take it out of the sea.
Alan tells Gordon he did a great job. Gordon says he'll have to wait for Virgil to return to collect him, so Alan says he'll call Scott. Alan tells Scott that everyone's fine, and whilst there are a few fires shooting out of the ocean, they'll burn themselves out in time. Scott says the emergency is over, and orders all Thunderbird craft to return to base.
A little later on, Jeff arrives back at Tracy Island. He asks for permission to land, but Scott tells him permission refused -Thunderbirds 1 and 2 are due to arrive at any time. Jeff says how do you like that, but Penelope says she likes it very much -Scott is controlling things correctly, just as his father does when he's on duty. Later on, Jeff tells everyone they did a swell job and he's proud of them. Virgil asks him how his vacation went.
Jeff says it's like this: he's come home to start work again, because he figured it's the only way he'll ever get any rest! He asks Scott that, if he doesn't mind, he'll have his desk back. Scott tells him he can have it, because now he needs a vacation! As Jeff sits back down, everybody starts laughing.